Heat exchanger, especially a heat exchanging module, for a motor vehicle

ABSTRACT

The invention relates to a heat exchanger for a motor vehicle. Said heat exchanger especially comprises a heat exchanging module provided with a plurality of pipes and corrugated ribs which are interconnected in the form of a network structure, and two lateral parts ( 1 ) which border the heat exchanging module on opposite sides. At least one break-off point ( 8 ) is provided on a lateral part ( 1 ).

The invention relates to a heat exchanger, in particular a heatexchanger module, for a motor vehicle.

In heat exchangers in the form of a heat exchanger module, that is tosay in which the condenser and the coolant cooler are connected to oneanother as a unit via corrugated ribs and side parts, temperaturechanges and associated periodically different temperature levels in theheat exchanger and coolant cooler result, due to the different thermalexpansion states, in stresses which may lead to leaks. Furthermore, thetemperature changes and the associated stress changes load the formedtube ends of the flat tubes of the heat exchanger module, and this maylead, here to leaks.

For this reason, in conventional heat exchangers, expansion beads in theside part are provided, as illustrated, for example, in FIG. 3 in theregion identified by a circle. The production of expansion beads of thistype requires special forming tools and an additional consumption ofmaterial as a result of the shaped-out beads.

The object of the invention is to improve a heat exchanger of this type.

According to the invention, a heat exchanger for a motor vehicle with aheat exchanger module is provided, which has a side part with at leastone predetermined breaking point. In this case, the predeterminedbreaking point lies preferably in the region of the tube forming or atan interface between the condenser part (in particular, flat-tubecondenser) and the coolant cooling part (in particular, coolant cooler)of the heat exchanger module.

Preferably, the predetermined breaking point is formed by webs, inparticular by three webs, which are separated from one another by meansof cutouts arranged in a V-shaped manner.

Preferably, the webs have a width of 0.5 to 2 mm, in particular 1 to 1.5mm, with the result that the predetermined breaking point breaks evenunder relatively low loads and the flat tubes of the heat exchanger areprotected.

Preferably, the heat exchanger is designed in such a way that a marginalregion of the side part is bent through approximately 90° along thelongitudinal edge of the side part and is interrupted in the region ofthe predetermined breaking point by cutouts.

Preferably, the webs are delimited laterally by cutouts, at least one ofwhich is of angular design in the direction of the webs, in particularwith an angle of 90° or less, that is to say is sharp-edged.

The invention is explained in detail below by means of an exemplaryembodiment, with reference to the drawing in which:

FIG. 1 shows a perspective illustration of a side part of a heatexchanger module;

FIG. 2 shows a top view of an end region of the side part of FIG. 1; and

FIG. 3 shows a perspective illustration of a side part of a heatexchange module according to the prior art.

FIG. 4 shows a perspective view of a predetermined breaking pointarranged in the region of a tube forming of a heat exchanger module.

FIG. 5 shows a perspective view of a predetermined breaking pointarranged at an interface between a condenser part and a coolant coolingpart of a heat exchanger module.

A heat exchanger according to the invention, in the form of a solderedall-aluminum heat exchanger module, has a flat-tube condenser, a coolantcooler, which comprise a plurality of flat tubes and corrugated ribsconnected to one another in the manner of a net structure, and two sideparts 1 which are located opposite one another and one of which isillustrated in FIGS. 1 and 2.

Reference is made below to FIG. 2, the configuration of the side parts 1being essentially symmetrical at both ends. The side part 1, a bentsheet aluminum part, has a marginal region 2 running essentially aroundthe entire side part 1 and bent to approximately 90° upward, that is tosay away from the flat-tube condenser and coolant cooler. The marginalregion 2 is interrupted, in an end region 3 of the side part 1, by twocutouts 4 which are arranged on the two longitudinal sides of the sidepart 1 and which have two edges 5 and 5′. In this case, the edgearranged further away from the end region 3 is designated by 5 and theedge lying nearer to the end region 3 is designated by 5′. In each case,formed approximately symmetrically, a cutout 6 running inward obliquelyto the longitudinal axis of the side part 1 is provided, spaced apartsomewhat from the edge 5, so that the two cutouts 6 are arranged in aV-shaped manner. The end region 3 and the middle region of the side part1 are connected to one another by means of three webs 7. The webs 7 havea width of approximately 1.5 to 2 mm and form a predetermined breakingpoint 8. In this case, the cutouts 4 and 6 are arranged in such a waythat in each case at least one sharp-edged corner region of the cutouts4 and 6 delimits a web 7, so that a high notch effect is achieved and,as a result, the predetermined breaking point 8 breaks even underrelatively low stresses. This occurs particularly in the event of atemperature change, as a result of which the coolant flat tubes expandin the direction of the block height, that is to say in the longitudinaldirection of the side part, and said stress thereby arises on the sidepart and leads to a predetermined break, with the result that thecoolant flat tubes are relieved of load. In this case, the side part ishighly stable in the direction of the block width, so that thepredetermined breaking point has no influence on the tensioning(cassetting) of the heat exchanger module.

FIG. 4 shows a perspective view of a predetermined breaking point 8arranged in the region of a tube forming 10 of a heat exchanger module.A header tank 16 is arranged in the end region 3 of the heat exchangermodule.

FIG. 5 shows a perspective view of a predetermined breaking point 8arranged at an interface between a condenser part 12 and a coolantcooling part 14 of a heat exchanger module.

LIST OF REFERENCE SYMBOLS

1 Side part 2 Marginal region 3 End region 4 Cutout 5, 5′ Edge 6 Cutout7 Web 8 Predetermined breaking point

1. A heat exchanger module suitable for use in a motor vehicle,comprising: a plurality of tubes and corrugated fins connected to oneanother to form a heat exchanger block; at least one header tankconnected to ends of the tubes; and two side parts which frame the heatexchanger module on opposite sides of the block, wherein at least onepredetermined breaking region is provided on at least one side part,wherein the side parts comprise a base portion and marginal regions;wherein the marginal regions of the side parts are bent throughapproximately 90° to form flanges along the longitudinal edges of theside part and at least one of the flanges along the longitudinal edge isinterrupted by a cutout; wherein the cutout completely interrupts theflange along the longitudinal edge of the side part and penetratespartially into the base portion of the side part, and wherein the cutoutcooperates with at least one aperture in the base portion of the sidepart to define between the cutout and the aperture a predeterminedbreaking point, and wherein the predetermined breaking point is adaptedto break when subjected to thermally-induced stress caused in the tubesduring operation of the heat exchanger.
 2. The heat exchanger module asclaimed in claim 1, wherein the predetermined breaking point is arrangedin the region where the tubes are connected to the header tank.
 3. Theheat exchanger module as claimed in claim 1, wherein the predeterminedbreaking point is formed by a web defined between the cutout and the atleast one aperture.
 4. The heat exchanger module as claimed in claim 2,wherein the at least one side part comprises two of said cutouts ongenerally opposing edges of the side part and each of said cutouts formsa predetermined breaking point with the at least one aperture.
 5. Theheat exchanger module as claimed in claim 4, comprising two apertures inthe base portion of the side part, one aperture cooperating with each ofsaid cutouts to define a web therebetween, wherein said two aperturescomprise slots that are arranged in V-shaped configuration with thediverging ends of the slots cooperating with the cutouts and theconverging ends of the slots form between them a further web, wherebythere is formed a V-shaped predetermined breaking region wherein thewebs are arranged at the three corners of the V-shaped predeterminedbreaking region.
 6. The heat exchanger module as claimed in claim 5,wherein the webs have a width of 0.5 to 2 mm.
 7. The heat exchangermodule as claimed in claim 3, wherein the cutouts are of rectilinearshape.
 8. The heat exchanger module as claimed in claim 7, wherein thecutouts include at least one edge which includes an angle of 90° or lesswith respect to the longitudinal edge.
 9. The heat exchanger module asclaimed in claim 6, wherein the width of the webs is 1 to 1.5 mm. 10.The heat exchanger module as claimed in claim 1, wherein the cutoutsform at least one rectilinear cutout in the base portion of the sideparts.
 11. The heat exchanger module as claimed in claim 1, wherein thecutouts form at least one sharp-edged corner region that defines thepredetermined breaking point.
 12. The heat exchanger module as claimedin claim 3, wherein the webs are formed entirely in the base portion ofthe side part.
 13. The heat exchanger module as claimed in claim 1,wherein the heat exchanger comprises a first heat exchanger and a secondheat exchanger that is different from the first heat exchanger and thatis arranged next to the first heat exchanger and is connected to thefirst heat exchanger by the side parts.
 14. The heat exchanger module asclaimed in claim 1, wherein the heat exchanger module comprises a firstheat exchanger and a second heat exchanger arranged parallel to oneanother, wherein the predetermined breaking point is arranged at aninterface between the first heat exchanger and the second heatexchanger.
 15. The heat exchanger module as claimed in claim 14, whereinthe first heat exchanger is a radiator and the second heat exchanger isa condenser.
 16. The heat exchanger module as claimed in claim 14,wherein the first heat exchanger and second heat exchanger are connectedto one another as a unit via the fins and the side parts.